The wind farm industry has been forced on the defensive after it emerged last month that the MoD believes the turbines at offshore wind farms are interfering with its radar. The department objects to almost all wind farms in the line of sight of its radar stations, it is claimed.

A number of major wind farm operators have now grouped together to stage a fightback, hiring Tetra Strategy, the agency headed by former Good Relations Political MD James O'Keefe.

The agency will lobby ministers and officials at the Department for Business, Enterprise and Regulatory Reform and the Department for Environment, Food and Rural Affairs.

It will argue that the MoD's objections mean millions of pounds of investment are at risk and that the Government's ambitious plans to meet up to a third of Britain's energy needs through offshore wind farms are in jeopardy.

According to The Times, the MoD has lodged last-minute objections to at least four onshore wind farms in the line of sight of its stations on the east coast because they make it impossible to spot aircraft.

The same objections are likely to apply to wind turbines in the North Sea, part of the massive renewable energy project announced by business and enterprise secretary John Hutton three months ago.

They would be directly in line with the three principal radar defence stations on the Northumberland, Yorkshire and Norfolk coasts.

The MoD denied that it made automatic objections to wind farms but said: 'We look at whether turbines will be in line of sight - in other words, if the radar can see the turbine. If it can, we know there will be an effect as we have evidence from trials.'